import 'package:flutter/material.dart';

class NewRouteRowCol3 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("New route"),
      ),
      body: Container(
        color: Colors.green,
        child: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisSize: MainAxisSize.max, //有效，外层Colum高度为整个屏幕
            children: <Widget>[
              Expanded(
                child: Container(
                  color: Colors.red,
                  child: Column(
                    mainAxisSize: MainAxisSize.max,//无效，内层Colum高度为实际高度
                    children: <Widget>[
                      Text("hello world "),
                      Text("I am Jack "),
                    ],
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}
